View Full Version : Build 54 - Gamma of RCX and Qt output not matching

12-14-2009, 08:37 PM
I'm using Snow Lepord and viewing QT files generated by RCX build 54 and the gamma does not match. An image showing the difference is attached.

Can you provide an explanation or fix for this?

It appears that there is approx. 0.4 gamma scaling happening in QT. A quick and dirty multiplication of the gamma on the brighter image by 0.6 appears to bring the images closer together.

As the default system gamma in Snow Leopard is now 2.2 not 1.8 I am wondering if this is an issue that's specific to Snow Leopard.



12-18-2009, 12:37 AM
Has anyone at Red duplicated or confirmed this?


01-09-2010, 05:31 AM
I resolved this and thought I'd pass along my conclusions.

This appears to be related to FC6 on Snow Leopard. Updating to FC7 resolves the issue and the RedAlert/RedCineX view now matches the exported Quicktimes.


Evan Giordanella
02-02-2010, 12:38 PM
I have noticed a gamma shift in h264 files made by rocket cine vs. compressor. Both in Snow Leopard. I thought the gamma issues were resolved by snow leopard. Is this perhaps a red rocket issue now?